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Cancer-killing combo: Viagra and the flu vaccine

“Strange bedfellows” doesn’t even begin to describe the drug combination that a new study published in OncoImmunology suggests may actually work together to combat cancer. According to the study, it appears that erectile dysfunction treatment, paired with a flu vaccine, can help reduce the spread of cancer.

The study specifically looked at cancer cells that are left behind following surgery to remove cancer tumors. While the surgical removal of cancerous tumors is usually quite effective, it has the terrible side effect of compromising the immune system, leaving the body vulnerable to cancer cells that might remain post-surgery.

“Usually, natural killer immune cells play a major role in killing metastatic cancer cells but surgery can create myeloid derived suppressor cells (MDSC), another kind of immune cell, which block the natural killer cells,” explains Mattha Busby in The Independent. “Researchers found that erectile dysfunction drugs block MDSCs, which allow the natural killer cells to fight the cancerous cells while the flu vaccine further stimulate the natural killer cells.”

The study used the two best known drugs for treating ED, sildenafil (Viagra) and tadalafil (Cialis), along with an inactivated influenza vaccine, Agriflu, in a mouse model mimicking the spread of cancer post-surgery. The researchers found that this drug combination resulted in far fewer metastases in the mouse lungs (see details).

Given these promising results, the senior author of the study, Dr. Rebecca Auer, who is surgical oncologist and head of cancer research at The Ottawa Hospital, is now heading the world’s first clinical trial of an erectile dysfunction drug and the flu vaccine in cancer patients.

Elizabeth Payne of the Ottawa Citizen reports that Ottawa Hospital nurse Jackie Fletcher, an abdominal cancer patient currently on leave following the removal of a large tumor, was the first person to join the trial. “She required surgery to remove the growth, but Fletcher said it is a type of cancer that can grow back, requiring more surgeries. She leaped at a chance to take part in a clinical trial that has potential to reduce the spread of cancer,” writes Payne.

“She admits she found the drug combination unusual. ‘I laughed and said I always wanted to try one of those erectile dysfunction drugs.’”